Messenger – The Messenger class is a lightweight way of passing messages between various ViewModel objects who do not need to be aware of each other. This is based on the Mediator implementation created by Marlon Grech and Josh Smith, as seen on Marlon’s blog (http://mvvmfoundation.codeplex.com/ )

MVVM – Misconceptions

No Code-behind

Views have to be DataTemplates

Converters are not needed

ViewModel completely wraps Model

Only Big projects need to implement MVVM

Summary

Model-View-ViewModel helps you and your customers to build better apps